The present invention generally relates to a heater and, more particularly, to a heater for a lighted signal mirror, preferably, for vehicles and the like, and wherein the heater diffuses the light used to illuminate the signal mirror.
The provision of side view mirrors, especially on automobiles and the like, is well known in the prior art. More specifically, side view mirrors heretofore devised and utilized are known to include familiar, expected, and obvious structural configurations or housings which mount to an exterior of the vehicle and have a reflective element or glass mirror.
Of course, it is not necessary to heat a mirror located in the open air, or the exterior mirror of a vehicle, unless the temperature of the mirror surface falls below the dew-point of the surrounding air, or if the mirror can no longer fulfill its function properly because the reflective surface thereon becomes fogged or is covered with ice or snow. Moreover, such mirrors located in the open air often become unusable because of increased humidity which precipitates as condensation on the mirror surface.
Devices for heating a reflective element or mirror are known. With most such mirrors, an electrical heating element is arranged adjacent to an inner surface of the mirror. Positive temperature coefficient (PTC) heaters, such as those disclosed in U.S. Pat. Nos. 4,857,711 and 4,931,627 To Leslie M. Watts, include a substrate having an electrical pattern thereon and an electrically resistive layer of material formed thereover such that the heater offers a resistance which increases in response to increasing temperatures.
As will be appreciated, many automobile accidents are caused by lane-changing, freeway merging or front-to-rear crashes. In an effort to curtail such accidents, turn indicators or signaling devices have recently been incorporated for use with side view mirrors of vehicles. When a turn signal is activated inside the vehicle, a flashing design or pattern appears within a predetermined area on the corresponding side mirror to alert drivers in the blind spot of the turning vehicle. Otherwise, the side view mirrors generally appear as regular rearview mirrors when the turn signal is not actuated or enabled. With the increased popularity of trucks, SUVs and vans coupled with the use of such vehicles for towing, the signal from the side view mirror may be the only indication driversxe2x80x94a few car lengths backxe2x80x94may have regarding intentions of the vehicle ahead. As will be appreciated, the taillights are often hidden by these trailer vehicles or by what is being towed.
In one form, such turn indicators include a mounting arranged to the rear side of the reflective element and within a blind cavity defined by a rear view mirror housing. An electrified light source, frequently including an LED array is provided within the mounting. As will be appreciated, the light source is operably connected to a turn signal indicator in the vehicle such that the light source emits a light directed toward a predetermined area on the rear surface of the mirror or reflective element in response to activation of the turn signal indicator. However, it has been observed that the light directed from the light source may have an objectionable intensity. Because of the visibility of the LEDs through the glass mirror, the mirror assembly may take on an unsightly appearance.
As can be appreciated, when adding a signal indicator to a mirror assembly, it is important to properly locate the signal indicator with respect to other components of the mirror assembly. Of course, precision and accuracy generally add to the overall cost of the mirror assembly.
Thus, there is a need and continuing desire for an economical heater capable of providing heat across substantially the entire face of the mirror including that section wherein a signal indication is provided and wherein the light emitted from the mirror for signaling is diffused to soften the light intensity and minimize an unsightly appearance of the light source used to direct light toward the rear surface of the mirror.
The present invention relates to a heater for a vehicle mirror assembly including a reflective element having inner and outer surfaces and a signal indicator with a light source positioned to face and direct light toward the inner surface of the reflective element. The signal indicator may be a turn signal, a braking light, or any other suitable form of signal indicator.
According to the present invention, the heater includes a heating element adapted to extend between the inner surface of the reflective element and the signal indicator. The heating element includes a substrate having an unobstructed area thereon arranged in predetermined relation relative to and through which light from the signal indicator light source is emitted.
The heating element defines a patterned opening arranged in registry with the unobstructed predetermined area on the substrate through which light from the signal indicator light source emitted. As such, and when the signal indicator is enabled, light is emitted through the heating element and directed toward the mirror to, ultimately, provide a lighted signal pattern discernable to drivers of overtaking vehicles.
The heating element for the heater preferably includes an electrical pattern on the substrate. A conductive layer of resistive material is also deposited on the substrate in operable combination with the electrical pattern. In a preferred embodiment, the conductive layer comprises a positive temperature coefficient resistive material which is substantially impermeable to light. In a preferred embodiment, the resistive material or thermistor layer defines the patterned opening for the heating element and through which the signal light pattern is emitted. Alternatively, the heating element could be a fixed resistance heater.
According to one aspect of the present invention, a light diffusing treatment is directly applied to at least the unobstructed predetermined area of the substrate exposed to the signal indicator light and in registry with the patterned opening in the conductive layer of material. In one form, the light diffusing treatment is directly applied to at least the unobstructed predetermined area of the substrate as a transparent diffuser coating. Alternatively, however, other forms of light diffusing treatments, including etching, painting, roll coating, or the like, can be directly applied to the predetermined area of the substrate to effect the transmissivity of the light passing therethrough. Regardless of the type of treatment used, when the signal indicator light source is enabled, diffused light passes from the heating element and, ultimately, through the mirror to provide the signal light pattern to other drivers. The application of a light diffusing treatment directly to the substrate allows inexpensive and simple production of diffused light to be emitted from the mirror assembly.
In a preferred embodiment, the substrate, the light diffusing treatment, the electrical pattern on the substrate, and the conductive layer are all substantially coextensive relative to each other. Moreover, in one form, the diffusing treatment preferably has a color added thereto such that a colored signal light pattern using diffused light will be visually emitted from the mirror assembly when the signal indicator light source is enabled. In another form, the diffusing treatment is applied directly to the substrate in a manner whereby allowing different lighting sources to be used in combination with the signal indicator without adversely affecting signal quality.
Another aspect of the present invention relates to providing a heater with the capability to heat the entire surface of the mirror or reflective element including the section of the mirror through which the lighted signal is emitted. In this embodiment, the electrical pattern provided on said substrate includes a first zone, extending across a majority of the inner surface of the mirror, and a second zone, arranged in substantially surrounding relation relative to the area on the substrate through which the signal light is emitted. The electrically resistive layer of material deposited on the substrate is arranged in operable combination relative to both the first and second zones of said electrical pattern whereby providing heating capability across substantially the entire of the mirror including that area on the mirror through which the signal for other drivers is provided.
In one form, the substrate for the heating element is provided with one or more locating or positioning apertures which facilitate placement or location of the heater element during assembly of the mirror. As will be appreciated, if the substrate of the heating element were to be misplaced relative to the signal indicator during assembly of the mirror, the area on the substrate through which the light of the lamp assembly is directed, along with the conductive coating arranged in substantially surrounding relation relative to the predetermined area on the substrate, can likewise be misplaced, thus, adversely affecting the signal light emitted from the signal indicator lamp assembly. To reduce such concerns, and according to a preferred embodiment, aperture positioning locators are provided on the substrate in edge registration with at least the electrical pattern on the substrate thereby providing an indicator for locating or positioning such apertures which aid in proper registration or assembly of and between the components of the mirror assembly. Notably, however, the apertures do not adversely affect the heating capabilities of the heating element because the heater is adapted to heat substantially the entire surface of the mirror, including the section of the mirror substantially adjacent the apertures.
The heating element furthermore preferably includes an adhesive layer deposited to the surface of the substrate arranged adjacent to the inner surface of the mirror. As such, the heating element adhesively bonds to the mirror. Preferably, a removable protective layer is disposed over the adhesive layer to facilitate transportation and shipping of the heating element. Another adhesive layer is preferably deposited to the surface of the electrical heating element disposed furthest from the inner surface of the mirror. With such design, a removable protective layer is disposed over the adhesive layer to facilitate transportation and shipping of the heating element. It should also be noted, in an alternative form of the invention, one of the adhesive layers can be provided with a patterned opening arranged in registry with the unobstructed area on the substrate of the heating element. In this embodiment, the light diffusing treatment would not necessarily have to be applied to the substrate, thereby possibly reducing manufacturing and/or assembly costs for the mirror.
A feature of the present invention involves providing a light diffusing signal mirror heating element.
Another feature of the present invention involves reducing the complexity and cost of producing a heated mirror assembly embodying a signal which is illuminated with diffused light.
Still another feature of the present invention involves providing a signal mirror heating element having the capability to heat substantially the entire surface of the mirror including that area of the mirror through which the signal light is emitted.
Yet another feature of the present invention involves providing a heater for a mirror assembly embodying a signal which is illuminated with diffused light and wherein the diffuser for the light is arranged substantially adjacent to an inner surface of the mirror, thus, eliminating a potential area for unclear and/or reduced light transmission.
Another feature of the present invention is to provide a heater for a mirror assembly embodying a signal which is illuminated with diffused light and wherein the heating element can be designed to modify the translucency of light emitted from the mirror.
Still another feature of the present invention is to provide a heater for a mirror assembly embodying a signal which is illuminated with diffused light and wherein the light diffusing treatment can be colored such that the signal lighting emitted from the mirror appears both diffused and colored thus, softening and equalizing the intensity of the light while concurrently aiding in the transmission of the signal light.
These and other features, aims, and advantages of the present invention will become more readily apparent from the following drawings, the detailed description, and the appended claims.